Fluorescence in situ hybridization (FISH) for direct visualization of bacteria in periapical lesions of asymptomatic root-filled teeth

Microbiology ◽  
2003 ◽  
Vol 149 (5) ◽  
pp. 1095-1102 ◽  
Author(s):  
Pia T. Sunde ◽  
Ingar Olsen ◽  
Ulf B. Göbel ◽  
Dirk Theegarten ◽  
Sascha Winter ◽  
...  

Whether micro-organisms can live in periapical endodontic lesions of asymptomatic teeth is under debate. The aim of the present study was to visualize and identify micro-organisms within periapical lesions directly, using fluorescence in situ hybridization (FISH) in combination with epifluorescence and confocal laser scanning microscopy (CLSM). Thirty-nine periapical lesions were surgically removed, fixed, embedded in cold polymerizing resin and sectioned. The probe EUB 338, specific for the domain Bacteria, was used together with a number of species-specific16S rRNA-directed oligonucleotide probes to identify bacteria. To control non-specific binding of EUB 338, probe NON 338 was used. Alternatively, DAPI (4′,6′-diamidino-2-phenylindole) staining was applied to record prokaryotic and eukaryotic DNA in the specimens. Hybridization with NON 338 gave no signals despite background fluorescence of the tissue. The eubacterial probe showed bacteria of different morphotypes in 50 % of the lesions. Rods, spirochaetes and cocci were spread out in areas of the tissue while other parts seemed bacteria-free. Bacteria were also seen to co-aggregate inside the tissue, forming microcolonies. Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis and treponemes of phylogenetic Group I were detected with specific probes. In addition, colonies with Streptococcus spp. were seen in some lesions. A number of morphotypes occurred that could not be identified with the specific probes used, indicating the presence of additional bacterial species. CLSM confirmed that bacteria were located in different layers of the tissue. Accordingly, the FISH technique demonstrated mixed consortia of bacteria consisting of rods, spirochaetes and cocci in asymptomatic periapical lesions of root-filled teeth.

2009 ◽  
Vol 58 (10) ◽  
pp. 1359-1366 ◽  
Author(s):  
Ali Al-Ahmad ◽  
Marie Follo ◽  
Ann-Carina Selzer ◽  
Elmar Hellwig ◽  
Matthias Hannig ◽  
...  

Oral biofilms are one of the greatest challenges in dental research. The present study aimed to investigate initial bacterial colonization of enamel surfaces in situ using fluorescence in situ hybridization (FISH) over a 12 h period. For this purpose, bovine enamel slabs were fixed on buccal sites of individual splints worn by six subjects for 2, 6 and 12 h to allow biofilm formation. Specimens were processed for FISH and evaluated with confocal laser-scanning microscopy, using probes for eubacteria, Streptococcus species, Veillonella species, Fusobacterium nucleatum and Actinomyces naeslundii. The number of adherent bacteria increased with time and all tested bacterial species were detected in the biofilm formed in situ. The general percentage composition of the eubacteria did not change over the investigated period, but the number of streptococci, the most frequently detected species, increased significantly with time (2 h: 17.7±13.8 %; 6 h: 20.0±16.6 %; 12 h: 24.7±16.1 %). However, ≤1 % of the surface was covered with bacteria after 12 h of biofilm formation in situ. In conclusion, FISH is an appropriate method for quantifying initial biofilm formation in situ, and the proportion of streptococci increases during the first 12 h of bacterial adherence.


2013 ◽  
Vol 33 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Maria Pihl ◽  
Julia R. Davies ◽  
Ann-Cathrine Johansson ◽  
Gunnel Svensäter

♦BackgroundPeritonitis is the leading cause of morbidity for peritoneal dialysis (PD) patients, and microbial biofilms have previously been identified on catheters from infected patients. However, few studies of catheters from patients without clinical signs of infection have been undertaken. The aim of the present study was to investigate the extent to which bacteria are present on catheters from PD patients with no symptoms of infection.♦MethodsMicrobiologic culturing under aerobic and anaerobic conditions and confocal laser scanning microscopy were used to determine the distribution of bacteria on PD catheters from 15 patients without clinical signs of infection and on catheters from 2 infected patients. The 16S rRNA gene sequencing technique was used to identify cultured bacteria.♦ResultsBacteria were detected on 12 of the 15 catheters from patients without signs of infection and on the 2 catheters from infected patients. Single-species and mixed-microbial communities containing up to 5 species were present on both the inside and the outside along the whole length of the colonized catheters. The bacterial species most commonly found were the skin commensals Staphylococcus epidermidis and Propionibacterium acnes, followed by S. warneri and S. lugdunensis. The strains of these micro-organisms, particularly those of S. epidermidis, varied in phenotype with respect to their tolerance of the major classes of antibiotics.♦ConclusionsBacteria were common on catheters from patients without symptoms of infection. Up to 4 different bacterial species were found in close association and may represent a risk factor for the future development of peritonitis in patients hosting such micro-organisms.


Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1821
Author(s):  
Ting He ◽  
Wei Shi ◽  
Song Xiang ◽  
Chaowen Huang ◽  
Ronald G. Ballinger

The influence of AlFeSi and Mg2Si phases on corrosion behaviour of the cast 6061 aluminium alloy was investigated. Scanning Kelvin probe force microscopy (SKPFM), electron probe microanalysis (EPMA), and in situ observations by confocal laser scanning microscopy (CLSM) were used. It was found that Mg2Si phases were anodic relative to the matrix and dissolved preferentially without significantly affecting corrosion propagation. The AlFeSi phases’ influence on 6061 aluminium alloy local corrosion was greater than that of the Mg2Si phases. The corroded region width reached five times that of the AlFeSi phase, and the accelerating effect was terminated as the AlFeSi dissolved.


Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 301
Author(s):  
Kathrin Malfeld ◽  
Nina Armbrecht ◽  
Holger A. Volk ◽  
Thomas Lenarz ◽  
Verena Scheper

In recent years sensorineural hearing loss was found to affect not exclusively, nor at first, the sensory cells of the inner ear. The sensory cells’ synapses and subsequent neurites are initially damaged. Auditory synaptopathies also play an important role in cochlear implant (CI) care, as they can lead to a loss of physiological hearing in patients with residual hearing. These auditory synaptopathies and in general the cascades of hearing pathologies have been in the focus of research in recent years with the aim to develop more targeted and individually tailored therapeutics. In the current study, a method to examine implanted inner ears of guinea pigs was developed to examine the synapse level. For this purpose, the cochlea is made transparent and scanned with the implant in situ using confocal laser scanning microscopy. Three different preparation methods were compared to enable both an overview image of the cochlea for assessing the CI position and images of the synapses on the same specimen. The best results were achieved by dissection of the bony capsule of the cochlea.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4958
Author(s):  
Jessa Marie V. Makabenta ◽  
Jungmi Park ◽  
Cheng-Hsuan Li ◽  
Aritra Nath Chattopadhyay ◽  
Ahmed Nabawy ◽  
...  

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of Escherichia coli and Pseudomonas aeruginosa. This study highlights a potential clinical application of the presented polymeric platform.


2001 ◽  
Vol 67 (11) ◽  
pp. 5273-5284 ◽  
Author(s):  
Holger Daims ◽  
Jeppe L. Nielsen ◽  
Per H. Nielsen ◽  
Karl-Heinz Schleifer ◽  
Michael Wagner

ABSTRACT Uncultivated Nitrospira-like bacteria in different biofilm and activated-sludge samples were investigated by cultivation-independent molecular approaches. Initially, the phylogenetic affiliation of Nitrospira-like bacteria in a nitrifying biofilm was determined by 16S rRNA gene sequence analysis. Subsequently, a phylogenetic consensus tree of theNitrospira phylum including all publicly available sequences was constructed. This analysis revealed that the genusNitrospira consists of at least four distinct sublineages. Based on these data, two 16S rRNA-directed oligonucleotide probes specific for the phylum and genus Nitrospira, respectively, were developed and evaluated for suitability for fluorescence in situ hybridization (FISH). The probes were used to investigate the in situ architecture of cell aggregates ofNitrospira-like nitrite oxidizers in wastewater treatment plants by FISH, confocal laser scanning microscopy, and computer-aided three-dimensional visualization. Cavities and a network of cell-free channels inside the Nitrospiramicrocolonies were detected that were water permeable, as demonstrated by fluorescein staining. The uptake of different carbon sources byNitrospira-like bacteria within their natural habitat under different incubation conditions was studied by combined FISH and microautoradiography. Under aerobic conditions, theNitrospira-like bacteria in bioreactor samples took up inorganic carbon (as HCO3 − or as CO2) and pyruvate but not acetate, butyrate, and propionate, suggesting that these bacteria can grow mixotrophically in the presence of pyruvate. In contrast, no uptake by theNitrospira-like bacteria of any of the carbon sources tested was observed under anoxic or anaerobic conditions.


2000 ◽  
Vol 41 (12) ◽  
pp. 69-77 ◽  
Author(s):  
J. C. Araujo ◽  
G. Brucha ◽  
J. R. Campos ◽  
R. F. Vazoller

In this study we investigated the development of anaerobic biofilm using a laboratory reactor. We were especially interested in comparing the organization of anaerobic cells (particularly those that are very common in domestic sewage sludge) in a hydrophilic (glass) versus a hydrophobic (polypropylene) surface. Fluorescent in situ hybridization (FISH) with domain and group specific probes directed against 16S ribosomal RNA were used to quantify microbial composition in the biofilm. FISH and confocal laser scanning microscopy (CLSM) were used to elucidate spatial distribution of microbes in the biofilms. Two experiments were carried out, one with pure methanogenic organisms and the other with a microbial anaerobic consortium. The pure methanogen cultures, Methanobacterium formicicum (DSM 1535); Methanosaeta concilli (DSM 3671) and Methanosarcina barkeri (DSM 800) were used to seed the modified Robbins Device (MRD) to allow the development of biofilms on polypropylene and glass surfaces during the 9-days experiment. The results showed that all the three species were colonizing both surfaces after two and nine days of experimental period. In another experiment, with polypropylene coupons only, MRD was seeded with a microbial anaerobic consortium and biofilm formation was studied during 11 days. At the end of this period, the biofilms generated were of uneven thickness with areas of minimal or no surface coverage and areas where the biofilm attained a thickness of 7.0 to 9.0 μm as revealed by CLSM. The results showed that the modified Robbins Device together with the fluorescent in situ hybridization and confocal laser scanning microscopy are suitable tools to study anaerobic biofilm development in different kinds of support materials.


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